nixos/polkit: don't enable by default

SUID wrappers really shouldn't be enabled by default, unless a consumer
relies on them. So in my opinion this falls upon the desktop
environments if needed or a user to explicltly enable this if wanted.

Most desktop environments and services like CUPS already enable polkit
by default, that should really be sufficient.

nixos/doc/manual/from_md/release-notes/rl-2205.section.xml

@@ -721,6 +721,14 @@
           <literal>tmux</literal>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          The polkit service, available at
+          <literal>security.polkit.enable</literal>, is now disabled by
+          default. It will automatically be enabled through services and
+          desktop environments as needed.
+        </para>
+      </listitem>
     </itemizedlist>
   </section>
 </section>

nixos/doc/manual/release-notes/rl-2205.section.md

@@ -245,4 +245,6 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - `programs.tmux` has a new option `plugins` that accepts a list of packages from the `tmuxPlugins` group. The specified packages are added to the system and loaded by `tmux`.
 
+- The polkit service, available at `security.polkit.enable`, is now disabled by default. It will automatically be enabled through services and desktop environments as needed.
+
 <!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->

nixos/modules/security/polkit.nix

@@ -12,11 +12,7 @@ in
 
   options = {
 
-    security.polkit.enable = mkOption {
+    security.polkit.enable = mkEnableOption "polkit";
-      type = types.bool;
-      default = true;
-      description = "Whether to enable PolKit.";
-    };
 
     security.polkit.extraConfig = mkOption {
       type = types.lines;